<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="../js/vue.js"></script>
</head>
<body>
    <div id="app">
        <div v-if="isShow" ref="self">测试div</div>
        <button @click="isShow=!isShow">更新</button>
    </div>
    <script>
        var vm = new Vue({
            el:'#app',
            data : {
                isShow:false
            },
            beforeUpdate(){
                console.log('更新之前');
                console.log(this.$refs.self);
            },
            updated(){
                console.log('更新之后');
                console.log(this.$refs.self);
            }       
        })
    </script>
</body>
</html>